Deep learning for vision‐based fall detection system: Enhanced optical dynamic flow

Accurate fall detection for the assistance of older people is crucial to reduce incidents of deaths or injuries due to falls. Meanwhile, vision‐based fall detection system has shown some significant results to detect falls. Still, numerous challenges need to be resolved. The impact of deep learning has changed the landscape of the vision‐based system, such as action recognition. The deep learning technique has not been successfully implemented in vision‐based fall detection system due to the requirement of a large amount of computation power and requirement of a large amount of sample training data. This research aims to propose a vision‐based fall detection system that improves the accuracy of fall detection in some complex environments such as the change of light condition in the room. Also, this research aims to increase the performance of the pre‐processing of video images. The proposed system consists of Enhanced Dynamic Optical Flow technique that encodes the temporal data of optical flow videos by the method of rank pooling, which thereby improves the processing time of fall detection and improves the classification accuracy in dynamic lighting condition. The experimental results showed that the classification accuracy of the fall detection improved by around 3% and the processing time by 40–50 ms. The proposed system concentrates on decreasing the processing time of fall detection and improving the classification accuracy. Meanwhile, it provides a mechanism for summarizing a video into a single image by using dynamic optical flow technique, which helps to increase the performance of image preprocessing steps.     

Looking on Heterogeneous Catalytic Systems from Different Perspectives: Multitechnique Approaches as a New Challenge for In Situ Studies

Adapting physico-chemical characterization techniques for in situ studies of real heterogeneous catalysts during conditioning, reaction, and deactivation processes is a research topic of growing importance. Up to now, in most studies only one single in situ technique is applied. However, new trends are focused on using a portfolio of several in situ methods to obtain comprehensive information on structure-reactivity relationships. This review discusses such application examples with the aim to point out the particular benefits that arise from multitechnique approaches for understanding processes like formation of active sites, interaction of those sites with reactant molecules, and catalyst deactivation. Except for Fourier-transform infrared spectroscopy and quasi-in situ X-ray photoelectron spectroscopy, the examples deal mainly with the combined use of bulk techniques such as electron paramagnetic resonance, ultraviolet/visible diffuse reflection spectroscopy, laser-Raman spectroscopy, temperature-programmed spectroscopy, X-ray diffraction, and X-ray absorption spectroscopy. However, although not being surface-sensitive per se, these techniques provide results relevant for the catalyzed reaction. Illustrative case studies comprise the investigation of (i) vanadia-based catalysts during selective oxidation and ammoxidation of toluene and during methanol synthesis, (ii) supported chromium oxides during octane aromatization, (iii) zeolite crystallization and catalysis, and (iv) a Cu/ZnO catalyst during methanol synthesis.     

Formal and relational governance in IT outsourcing: substitution,complementarity and the role of the psychological contract

This study aims to contribute to the literature on IT outsourcing governance by advancing our understanding of mechanisms of substitution and complementarity between formal and relational governance. Our study illustrates certain conditions under which substitution and complementarity can occur and depicts a two‐way causal relationship between them. Our examination further provides a more in‐depth assessment of relational governance by using the concept of the psychological contract. Our results demonstrate that the psychologically binding nature of the psychological contract makes it a particularly forceful substitute to formal governance, while its associations with other relationship aspects make it a forceful complement.     

Vicious and virtuous circles of offshoring attitudes and relational behaviours. A configurational study of German IT developers

Prior research has shown that the success of offshoring is affected by relational behaviours of the employees involved in an offshoring collaboration. However, hardly anything is known about the attitudes that onshore colleagues hold towards offshoring, and how such offshoring attitudes affect relational behaviours towards offshore colleagues. We therefore present an interpretivist, qualitative case study that explores the offshoring attitudes of German information technology developers. We found that offshoring attitudes affected relational behaviours towards Indian offshore colleagues, in terms of (1) treating Indian colleagues as fellow team members as opposed to suppliers; (2) spending more or less effort in communication and knowledge transfer; and (3) supporting vs. avoiding the task transfer. These relational behaviours fed back into participants' offshoring attitudes, leading to vicious and virtuous circles. The circles created two contrasting configurations of offshoring attitudes and relational behaviours, driven by opposing forces within the departmental context. Our findings highlight the value of taking a configurational perspective for understanding offshoring success and for identifying drivers that need to be managed in order to achieve favourable configurations. We suggest that future research should further expand the typology of attitude‐behaviour configurations and could apply theories of efficacy, self‐reinforcing spirals and planned behaviour.     

Coupled Crystal Plasticity–Phase Field Fracture Simulation Study on Damage Evolution Around a Void: Pore Shape Versus Crystallographic Orientation

Various mechanisms such as anisotropic plastic flow, damage nucleation, and crack propagation govern the overall mechanical response of structural materials. Understanding how these mechanisms interact, i.e. if they amplify mutually or compete with each other, is an essential prerequisite for the design of improved alloys. This study shows—by using the free and open source software DAMASK (the Düsseldorf Advanced Material Simulation Kit)—how the coupling of crystal plasticity and phase field fracture methods can increase the understanding of the complex interplay between crystallographic orientation and the geometry of a void. To this end, crack initiation and propagation around an experimentally obtained pore with complex shape is investigated and compared to the situation of a simplified spherical void. Three different crystallographic orientations of the aluminum matrix hosting the defects are considered. It is shown that crack initiation and propagation depend in a non-trivial way on crystallographic orientation and its associated plastic behavior as well as on the shape of the pore.     

Uptake of the cyanobacterial toxin cylindrospermopsin in Brassica vegetables

Toxin-producing cyanobacterial species are increasingly being found in freshwater systems. However, literature on the impact of many cyanobacterial toxins on plants is scarce. Cylindrospermosin (CYN), a secondary metabolite of cyanobacteria such as Cylindrospermopsis and Aphanizomenon species, is a potent hepatotoxin and protein synthesis inhibitor. Worryingly, CYN is increasingly found in surface and drinking water worldwide causing human and animal intoxications. Further, exposure of crop plants to CYN by irrigation with contaminated water has already been shown. Therefore, in this study, horticulturally important and highly consumed Brassica species were investigated to determine the level of CYN in the leaves after exposure of the roots to the toxin. Treatment of Brassica oleracea var. sabellica, Brassica juncea, and Sinapis alba under varying experimental conditions showed significant CYN uptake, with CYN levels ranging from 10% to 21% in the leaves compared to the CYN concentration applied to the roots (18–35 μg/l). In seedlings, CYN concentrations of up to 49 μg/g fresh weight were observed. Thus, crop plants irrigated with CYN-containing water may represent a significant source of this toxin within the food chain.     

Morphology and properties of foamed high crystallinity PEEK prepared by high temperature thermally induced phase separation

Polyetheretherketone (PEEK) is a high-performance semi-crystalline thermoplastic polymer with outstanding mechanical properties, high thermal stability, resistance to most common solvents, and good biocompatibility. A high temperature thermally induced phase separation technique was used to produce PEEK foams with controlled foam density from PEEK in 4-phenylphenol (4PPH) solutions. Physical and mechanical properties, foam and bulk density, surface area, and pore morphology of foamed PEEK were characterized and the role of PEEK concentration and cooling rate was investigated. Porous PEEK with densities ranging from 110 to 360 kg/m³ with elastic moduli and crush strength ranging from 13 to 125 MPa and 0.8 to 7 MPa, respectively, was produced.     

Assessment of Tailor-Made HPMC-Based Matrix Minitablets Comprising a Weakly Basic Drug Compound

Tailor-made, pH-controlled matrix minitablets based on different HPMC types were developed comprising the weakly basic drug dipyridamole. The incorporation of pH modifiers, i.e., fumaric and succinic acid, enhanced the drug release at pH 6.8. Assessing the drug release, acid release, and the microenvironmental pH (pH_M) provided detailed understanding of pH-controlled mini-matrices.

The extent and duration of pH_M alteration was more pronounced in presence of fumaric acid. Minitablets based on the fast dissolving Methocel K100LV (≤ 100 cps) showed simultaneous release rates of dipyridamole and fumaric acid with a constant low average pH_M.